1. Field of the Invention
The present invention relates generally to vehicles having an electric brake and an electric clutch, and more specifically to control circuitry for controlling the electric brake and clutch and for permitting actuation of the clutch only when the brake circuit is operational.
2. Description of the Prior Art
Many types of vehicles utilize an electric clutch with an integral electric brake. For example, lawn and garden tractors and utility vehicles often include a power take off (PTO) engaged by an electric clutch to power accessories such as lawn mowers. Various fail safe systems have been employed in the past to engage a PTO brake under certain conditions. One such system included fail safe brakes with springs to automatically apply the brakes and required large clutch coils to overcome the spring pressure during normal operation of the vehicle. This type of system also required a relatively precise gap adjustment for reliable clutch operation. In systems wherein electric power must be supplied to energize the brake, continued brake operation for a period of time after de-energization of the clutch without excessive drain on the battery has been a problem.
In addition, we have heretofore been unaware of a reliable and relatively simple and economical electrical control system for a brake which senses the presence of a good brake circuit before allowing engagement of the clutch.